The described subject matter relates generally to gas turbine engines, and more specifically to rotor blades for gas turbine engines.
Gas turbine engine airfoils, particularly those blades and vanes exposed to hot combustion products are provided with internal cooling cavities. To ensure circulation of coolant (e.g., air or steam) and provide sufficient convective cooling, the internal cooling cavities often include a serpentine portion through which the coolant is intended to make at least one full downward pass through the airfoil under most normal operating conditions.
Though well known and effective for various cooling applications, serpentine passages have relatively high pressure losses due to the need for the coolant to repeatedly change flow directions. Increased coolant pressure losses result in more coolant drawn from the engine working fluid to provide required airfoil cooling. This can increase parasitic losses and reduce engine efficiency. As such, a need has been identified for an internally cooled airfoil providing effective convective cooling and reduced pressure loss.